Clunking when engaging blades

I have a 1yr old (not even actually)Toro 44'' floating deck walk-behind with a 12.5 kaw. Since new this machine gives a nice big clunk when engaging the blades. It seems to be comming from the right side spindle area. It doesn't do this after I hose the machine off and engage the blades. Is this normal? Or is something out of adjustment/broken? Any suggestions? Thanx, Scott

There should be three nuts holding the plate up on the clutch,above that are springs check your owners man out,
there is a "air gap" setting for the clutch check this,while your under there check to see if the bolt holding the clutch to the engine has backed off and bent.been there done that.just something else to look at.one more thing to look at, the strip of metal hold the cover of the clucth fits in a slot check how worn it is and the tightness of this bolt.